Is Nummular Eczema an Autoimmune Disorder?

Nummular eczema, like other types of eczema, can be difficult to diagnose. Flare-ups are often caused by a combination of factors.

Environmental factors

• Cold, dry air
• Sudden temperature changes
• Harsh chemicals, such as alkaline materials, solvents, and acids
• Household irritants, such as certain soaps, detergents, fabrics, and cleaning products
• Industrial or workplace chemicals
• Metals, such as nickel and chromium
• Certain fabrics
• Stress
• Common allergens

Risk factors 

• Dry skin
• Hot water baths
• Family history of allergies or asthma
• Family or medical history of atopic dermatitis
• Working or living in an environment that exposes you to certain triggers
• Injury or trauma to the skin, including surgery, burns, and insect bites
• Side effects of certain medications
• Poor circulation in the lower extremities

Although the specific cause of nummular eczema is unknown, multiple studies show that it is more common in those with dry, sensitive skin. This type of skin gets irritated easily by external irritants, such as lotions, ointments, soaps, detergents, and rough clothing.

The initial signs of nummular eczema are usually little red spots or bumps on the skin that gradually come together to create larger pink, reddish-brown patches that can range in size from a few millimeters to several centimeters. Other common indications and symptoms include:

• Swollen patches
• Blisters around the patches that ooze pus
• Inflammation and itching around the patches

With time, the blisters may dry up and produce dry, scaly patches with a clear center, resembling a ringworm infection. If not treated promptly, nummular eczema can linger for weeks, months, or years, or it can recur and leave permanently discolored skin. If left untreated, nummular eczema can occasionally lead to infection:

• Yellow crusting
• Red, hot, tender, or swollen skin
• Fatigue
• Mild fever and chills

Duration of nummular eczema can vary greatly. Some cases last only a few weeks, whereas others last months or years. If you suspect you have the condition, consult a doctor for proper evaluation.

Nummular eczema is an incurable chronic skin disorder. However, following a treatment plan can help you manage symptoms and live relatively comfortably with the condition.

Treatment begins with avoiding your specific triggers or irritants, as well as the application of moisturizers for dry skin. However, since even low-strength, over-the-counter medicines can worsen the problem, your doctor may recommend several different kinds of therapies, creams, lotions, and other medications before finding what works best for you. In extreme cases of inflammation, corticosteroids could be required.

Medications to treat nummular eczema flare-ups include:

• Antihistamines
• Oral corticosteroids
• Phototherapy (therapeutic ultraviolet light exposure)
• Topical corticosteroids
• Topical immunomodulators
• Topical tar preparations
• Antimicrobials

Nummular eczema is not a serious condition. Intense scratching, however, can lead to bacterial or fungal diseases or cellulitis. Cellulitis complications can be severe if left untreated or inadequately handled. You can reduce your risk of major complications by adhering to the treatment plan recommended by your doctor.

In addition to having an integrated treatment plan that includes medications, a few other practices can reduce or prevent your symptoms:

• Avoiding chlorinated swimming pools, saunas, and hot tubs
• Avoiding overwashing or scrubbing the skin
• Taking an oatmeal bath or using oatmeal soap to relieve itching
• Using a humidifier
• Using cool, wet compresses to relieve itching
• Use lukewarm water when bathing and showering
• Keeping skin dry
• Wear loose and breathable clothing
• Protecting yourself from extreme temperatures